1. Field of the Invention
This invention pertains in general to the visual representation of information and in particular to techniques for displaying information on electronic maps.
2. Description of the Related Art
People use Internet-based electronic maps for a variety of purposes. Initial Internet-based map services allowed people to view street maps for cities and other geographic areas. People often used these services to obtain driving directions. More recent Internet-based services allow people to view more detailed maps. For example, people can now view satellite imagery, topographical data, and 3-D representations of buildings and other structures on maps. As a result, people now use Internet-based maps for many purposes other than for driving directions, such as for house and job hunting.
Even though there is a wide variety of map data available on the Internet, there are still many types of data that either cannot be viewed on maps, or are not well-represented on the maps. For example, a person hunting for a house might be interested in school districts, average housing prices, average incomes for a neighborhood, driving distances to work or shopping, etc. This information is often available on the Internet but cannot be viewed on a map.
If the data can be viewed on a map, the data are often displayed in a manner that reduces the effectiveness of the map. For example, one way to show school districts on a map is to present a static overlay that illustrates the district boundaries. Similarly, average housing prices can be shown by shading regions of the map with different colors representing the prices. A difficulty with representing data in this way is that the map quickly becomes cluttered with too much information and becomes difficult to comprehend.
Therefore, there is a need in the art for a way to display multiple types of data on a map without making the map difficult to comprehend.